Support is requested for the continuation of human temporal bone histopathology studies of 1) congenital anomalies, 2) Meniere's disease, 3) sudden hearing loss, 4) facial palsy, and 5) other problems of the ear. In addition to the classic histopathological process and studies, these studies employ unique computer three-dimensional (3-D) reconstruction and measurement methods and special specimen removal technique which has provided unique large, specimens (temporal bones and infratemporal fossa structures). These techniques permit the study of 3-D anatomy, embryology, phylogeny, and pathology of the inner and middle ears and infratemporal fossa structures. In our laboratory more than 1700 temporal bone specimens are either available for study or are being processed. Approximately 165 of our specimens include the infratemporal fossa structures. Only a few other laboratories in the United States have such large collections and no other laboratory has specimens with the infratemporal fossa structures, which we have found invaluable in gaining new information about the anatomy and pathology of the human ear. Furthermore, approximately 25 temporal bone-infratemporal fossa specimens will be added per year; appropriate cases will also be utilized in the proposed studies. An increased understanding of the anatomy and pathology of the human temporal bone and its surrounding structures forms the foundation for improved understanding of clinical problems in otology, audiology, genetics and neurology. Such understanding is essential to better patient care. In order to expand our knowledge, however, we must continue to collect and to examine specimens that include the infratemporal fossa structures and that have been processed for three-dimensional reconstruction and measurement.